the commentary says this is a causal particle expressing the writer’s opinion. I do not find this shade of meaning in dictionaries.
LSJ
ἅτε, properly acc. pl. neut. of ὅστε (as in Il. 11.779, 22.127).
I just as, as if, so as, ἅ. σήριον ἄστρον prob. in Alcm. 23.62, cf. Pi. O. 1.2, P. 4.30, Hdt. 5.85, S. Aj. 168 (lyr., s. v. l.); τιμᾶν τινα ἅ. ἱερόφαντιν Jul. Or. 7.221c.
II causal, inasmuch as, seeing that, with part., ἅτε τὸν χρυσὸν ἔχων Hdt. 1.154, cf. 102; Cratin. 295, Ar. Pax 623, Th. 4.130, etc.: with gen. abs., ἅτε τῶν ὁδῶν φυλασσομένων Hdt. 1.123, cf. Pl. Smp. 223b, etc.:—with part. omitted, δίκτυα δοὺς [αὐτῷ] ἅτε θηρευτῇ [ὄντι] Hdt. 1.123, etc.; ἅ. γένους προμάτωρ dub. in A. Th. 140 (lyr.); ἅ. δή Hdt. 1.171; ἅ. δὴ οὖν Pl. Prt. 321b; ὡς ἅ. freq. in Olymp. in Mete. 39.12, al.—Rare in Trag., and only in lyr.